Plant seeds include a germination step or phase as part of their growth cycle. In general, germination refers to the resumption of growth by an embryo in a seed after a period of dormancy. This resumption of growth occurs when a seed is exposed to suitable environmental conditions, including suitable temperature; adequate water and oxygen. Seeds, even in dormancy are respiring, but at a very slow rate. As the heat increases, the respiration rate will increase, regardless of the other conditions present. Absent proper temperature, moisture and oxygen, a seed will remain dormant.
Many food stuffs for human consumption are seeds. These include cereal grains, rice, wheat, corn, barley and oats. Plant seeds are also used in or as medicinal products, e.g., linseed oil, soybean oil and clothing, e.g., cottonseed. In some cases, seeds can not be used as intended if germination occurs.
Currently, dehydration is used to suppress undesired germination in seed products. Dehydration techniques can preclude germination, however, in some cases these techniques have an unacceptable effect on final product quality. For example, popcorn seed germination can be terminated by dehydration of the seed from about 14% to about 5%. However, even if rehydrated the popping capacity of such dehydrated corn seed is reduced to commercially unacceptable levels.
In the case of popcorn seed the need to terminate germination is especially important. Several countries, including Australia, do not allow importation of popcorn seed absent proof of complete seed devitalization. Accordingly, there is a need for an improved method to devitalize seed products, such as corn seed without adverse impact on product quality.